In the Pacific Northwest, our most common termite is the Pacific Dampwood termite. It occurs anywhere that there is dampwood. It is common to almost every yard, in every neighborhood. They can be found in fence posts, utility posts, tree stumps, any dead wood found in living trees, and sometimes in houses.
The swarmers are large, dark colored, and the swarms happen in late summer every year. If you see just a few of these insects, especially with wings, they probably just flew to your home from some nearby nest. They should not be a threat to your home, unless there is a moisture problem present.
To make sure that there is no moisture problem present, you should consider having your home inspected every year or two.
If you do have a moisture problem in your home, and the moisture problem does not have to be severe, a remedial treatment, along with recommendations on moisture control should take care of this problem.